In a lithium-sulfur battery, the cathode is made of sulfur and the anode is made of elemental lithium. During electrical discharge process, the elemental lithium loses electrons to become lithium-ion, and the sulfur reacts with the lithium-ion and electrons to produce lithium sulfides. A reaction equation is: S8+16Li++16e−1=8Li2S. A lithium-sulfur battery has advantages of low-cost, environmental friendliness, good safety, and high theoretical specific capacity.
A separator is an important component in the lithium-sulfur battery. The separator separates the cathode and the anode to avoid an internal short-circuit. However, the lithium-sulfur battery separator obtained by a conventional method is difficult to inhibit polysulfide diffusion. The polysulfide would be shuttled between the cathode and the anode, an irreversible damage to a structure of the cathode containing sulfur would be occurred. Thus the specific capacity and cycling stability of the lithium-sulfur battery would be limited.